Page 217 - MEGIN Book Of Abstracts - 2023

Here, we propose a novel extraction method for IEDs Department of Neurology, Tangshan Gongren Hospital,
using a T/k type of blind source separation (BSST/k). Tangshan 063000, China; Department of Neurology, Xuanwu
Hospital, Capital Medical University, Beijing 100053, China;
METHODS We applied BSST/k with seven patients with Beijing Key Laboratory of Neuromodulation, Beijing 100053,
focal epilepsy to test the accuracy of identification of China; Center of Epilepsy, Beijing Institute for Brain Disorders,
IEDs. We conducted comparisons of the results of BSS Beijing 100053, China; MEG Center, Division of Neurology,
components with those obtained by visual inspection Cincinnati Children's Hospital, Medical Center, Cincinnati,
in sensor-space analysis. OH 45220, USA; Department of Neurology, Hebei Medical
University, Shijiazhuang 050017, China; Department of Neu-
RESULTS BSST/k provided better signal estimation of rology, Hebei General Hospital, Shijiazhuang 050051, China;
IEDs compared with sensor-space analysis. Importantly, Department of Neurology, Xuanwu Hospital, Capital Medical
BSST/k was able to uncover IEDs that could not be University, Beijing 100053, China; Beijing Key Laboratory of
detected by visual inspection. Furthermore, IED com- Neuromodulation, Beijing 100053, China; Center of Epilepsy,
ponents were clearly extracted while preserving spike Beijing Institute for Brain Disorders, Beijing 100053, China.
and wave morphology. Variable IED waveforms were Electronic address: [email protected]
decomposed into one dominant component.
OBJECTIVE The project aimed to determine the altera-
CONCLUSIONS BSST/k was able to visualize the tions in the effective connectivity (EC) neural network
spreading signals over multiple channels into a single in patients with insular epilepsy based on interictal
component from a single epileptogenic zone. BSST/k high-frequency oscillations (HFOs) from magnetoen-
can be applied to focal epilepsy with a simple param- cephalography (MEG) data.
eter setting.
METHODS We studied MEG data from 22 insular
SIGNIFICANCE Our novel method was able to high- epilepsy patients and 20 normal subjects. Alterations
light IEDs with increased accuracy for identification of in spatial pattern and connection properties of the
IEDs from multi-channel MEG data. patients with insular epilepsy were investigated in the
entire brain network and insula-based network.
Keywords: Blind source separation, Interictal epileptiform
discharges, Magnetoencephalography, Time-delayed RESULTS Analyses of the parameters of graph theory
correlation revealed the over-connectivity and small-world con-
figuration of the global connectivity patterns observed
Clinical neurophysiology: official journal of the in the patients. In the insula-based network, the
International Federation of Clinical Neurophysiology insular cortex ipsilateral to the seizure onset displayed
(2020), Vol. 131, No. 2 (31887614) (3 citations) increased efferent and afferentEC. Left insular epi-
lepsy featured strong connectivity with the bilateral
hemispheres, whereas right insular epilepsy featured
Altered effective connectivity network in patients increased connectivity with only the ipsilateral hemi-
with insular epilepsy: A high-frequency oscillations sphere.
magnetoencephalography study (2020)
CONCLUSIONS Patients with insular epilepsy display
Yin, Chunli; Zhang, Xiating; Xiang, Jing; Chen, Zheng; Li, alterations in the EC network in terms of both whole-
Xin; Wu, Siqi; Lv, Peiyuan; Wang, Yuping brain connectivity and the insula-based network during
interictal HFOs.
Department of Neurology, Xuanwu Hospital, Capital Medical
University, Beijing 100053, China; Department of Neurol- SIGNIFICANCE Alterations of interictal HFO-based
ogy, Hebei Medical University, Shijiazhuang 050017, China; networks provide evidence that epilepsy networks,

 ontents  Index 196
C